Coles ice cream sandwich causes ants to ‘flee in terror’

They don't melt in the sun, and even the ants are "fleeing in terror" from the tasty treat, according to one NSW customer, who took to the supermarket's Facebook page on Monday to report her experience.

As Grafton grandmother Mary Salter explained, at about 5pm on Friday her grandson chucked a "skitz" when his ice cream broke in two, so he threw it out. "One half landed on [the] back cement the other half onto the lawn," she wrote.

"I thought I would leave the pieces for the cats/birds/dog even - ants maybe? I have watched with interest that none of the above would go near it - not even the ants. The (?) ice cream has not melted and there the two pieces sit. Now I am a little concerned just what is in this 'treat'.

"Can you please explain why after four days in 26-degree heat on cement it has not melted or nothing has volunteered to eat it ... [It is] still in direct sun, still not melted away, still ants fleeing in terror!"

Ms Salter encouraged others who had bought a Coles ice cream sandwich - which retails for just $3 for a pack of four - to give it a go. "Please, please do what I have done, break it, throw each half out and see if you can persuade it to melt or a creature to eat it," she wrote.

"At least I now know I can take them camping, no refrigeration needed. And they are ant-proof - on a winner here ... Will be very interested in what the diagnosis is."

In 2014, US retailer Walmart faced similar questions after Cincinnati TV station WCPO conducted a melting test on several different ice cream brands, finding that Walmart's ice cream sandwich did not melt when left in the sun.

"Ice cream melts based on the ingredients including cream," a Walmart spokesman said at the time. "Ice cream with more cream will generally melt at a slower rate, which is the case with our Great Value ice cream sandwiches."

Product review site Consumer Reports added: "Manufacturers add gums and other ingredients like calcium sulfate and mono diglycerides to help control the melting rate of ice cream. They are also added to stop large crystal formations from forming when the products are taken in and out of the freezer."

Debunking website Snopes concluded that while "the fact that Walmart Great Value brand ice cream seemingly doesn't melt may unnerve some people", all of its ingredients had been deemed safe for consumption by the Food and Drug Administration.

Ms Salter told news.com.au she didn't care what Americans were eating. "We want to know what Coles are feeding us Aussies," she said. "It possibly contains a cure for cancer or longevity at the very least."

A Coles spokesperson told news.com.au the supermarket giant had not added milk solids to its dark chocolat.

"As our milk chocolate and dark chocolate blocks are manufactured in the same facility, we have decided to itemise milk solids on our labelling for the sake of consumers with allergies.

"The cocoa used in our Coles Dark Chocolate blocks was grown and harvested in a sustainable way and is UTZ certified. UTZ stands for sustainable farming and better opportunities for farmers, their families and our planet."